The present invention is intended particularly for, although not necessarily limited to, utilization in connection with a small, hand held, fluid-driven appliance, such as a power toothbrush. Electrically driven power toothbrushes are well known and widely utilized. Recently, improvements in the design and construction of fluid motors has made it possible to incorporate a water driven motor into the base of a hand held toothbrush appliance, in a manner to provide a brushing device having superior functional and other characteristics. Certain aspects of such a device are disclosed and claimed in our earlier United States patent application Ser. No. 848,807, filed Nov. 7, 1977 now U.S. Pat. No. 4,175,299.
In the operation of a water driven appliance, such as a toothbrush, provision must be made for easy movement of the appliance in a universal manner, to accommodate all of the various natural motions and orientations involved in brushing all of the surfaces of the teeth and gums. At the same time, provision must be made for containing a rather substantial fluid pressure, at least on the high pressure side of the fluid connection. These two requirements, of course, tend to be somewhat contradictory. However, the arrangement of the invention provides for a highly optimized solution to the problems.
In accordance with the invention, a bidirectional fluid hose connection, between a fluid source and a hand held appliance, is provided in the form of a dual concentric tube arrangement, with each tube being provided with a highly simplified yet effective swivel connection at each end to accommodate relative rotation of the appliance without twisting and kinking the tubing. The inner tubing element, according to the invention, is constructed of a flexible, plastic material suitable to withstand the inlet-side pressure to which the device will be exposed. The larger, outer tubing element is likewise constructed of a flexible plastic material, but since it is connected to exhaust, it need not be designed to withstand significant pressure. Since the inner, high pressure element is of relatively small diameter, wall stresses per unit of pressure are minimized. Moreover, since the high pressure element is wholly concealed within the larger outer element, the materials utilized in the high pressure tubing may be selected exclusively on the basis of functional considerations and without regard to cosmetic aspects. The outer tubing, on the other hand, may be selected primarily to satisfy cosmetic considerations, since the functional requirements imposed on it are relatively minimal. The concentric hose construction not only facilitates easy relative rotation of the hand held appliance, but also accommodates neat and easy coiling the tubing for storage of the appliance after use.
In accordance with one of the specific aspects of the invention, simplified and economical, yet highly effective arrangements are provided for engaging the concentric tubing elements in operative relation with both the hand held appliance and a faucet attachment fitting, in a manner providing for relative rotational movement of the tubing, appliance and fitting. The arrangement of the invention enables a swivel connection to be provided without adding significantly to the physical bulk or weight of the elements, both important considerations in the design of a hand held appliance, such as a power toothbrush.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of preferred embodiments and to the accompanying drawings.